/*
 * Copyright 2011-2013 Blender Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "stdosl.h"
#include "node_texture.h"

/* Brick */

float brick_noise(int ns) /* fast integer noise */
{
  int nn;
  int n = (ns + 1013) & 2147483647;
  n = (n >> 13) ^ n;
  nn = (n * (n * n * 60493 + 19990303) + 1376312589) & 2147483647;
  return 0.5 * ((float)nn / 1073741824.0);
}

float brick(point p,
            float mortar_size,
            float mortar_smooth,
            float bias,
            float BrickWidth,
            float row_height,
            float offset_amount,
            int offset_frequency,
            float squash_amount,
            int squash_frequency,
            output float tint)
{
  int bricknum, rownum;
  float offset = 0.0;
  float brick_width = BrickWidth;
  float x, y;

  rownum = (int)floor(p[1] / row_height);

  if (offset_frequency && squash_frequency) {
    brick_width *= (rownum % squash_frequency) ? 1.0 : squash_amount;           /* squash */
    offset = (rownum % offset_frequency) ? 0.0 : (brick_width * offset_amount); /* offset */
  }

  bricknum = (int)floor((p[0] + offset) / brick_width);

  x = (p[0] + offset) - brick_width * bricknum;
  y = p[1] - row_height * rownum;

  tint = clamp((brick_noise((rownum << 16) + (bricknum & 65535)) + bias), 0.0, 1.0);

  float min_dist = min(min(x, y), min(brick_width - x, row_height - y));
  if (min_dist >= mortar_size) {
    return 0.0;
  }
  else if (mortar_smooth == 0.0) {
    return 1.0;
  }
  else {
    min_dist = 1.0 - min_dist / mortar_size;
    return smoothstep(0.0, mortar_smooth, min_dist);
  }
}

shader node_brick_texture(int use_mapping = 0,
                          matrix mapping = matrix(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0),
                          float offset = 0.5,
                          int offset_frequency = 2,
                          float squash = 1.0,
                          int squash_frequency = 1,
                          point Vector = P,
                          color Color1 = 0.2,
                          color Color2 = 0.8,
                          color Mortar = 0.0,
                          float Scale = 5.0,
                          float MortarSize = 0.02,
                          float MortarSmooth = 0.0,
                          float Bias = 0.0,
                          float BrickWidth = 0.5,
                          float RowHeight = 0.25,
                          output float Fac = 0.0,
                          output color Color = 0.2)
{
  point p = Vector;

  if (use_mapping)
    p = transform(mapping, p);

  float tint = 0.0;
  color Col = Color1;

  Fac = brick(p * Scale,
              MortarSize,
              MortarSmooth,
              Bias,
              BrickWidth,
              RowHeight,
              offset,
              offset_frequency,
              squash,
              squash_frequency,
              tint);

  if (Fac != 1.0) {
    float facm = 1.0 - tint;
    Col = facm * Color1 + tint * Color2;
  }

  Color = mix(Col, Mortar, Fac);
}
